Dehydrator



Dec, 18, 1951 H, H. scHULsTADT DEHYDRATOR 2 SHEETS-SHEET l Filed May 15,1946 WITNESS ATTORNEY Dea 18, 1951 H. H. scHLJLsTADT 2,579,053

DEHYDATOR Filed May l5, 1946 2 SHEETS-SHEET 2 WITNE'StS` 2 Patented Dec.18, 1951 DEHYDRATOR Herbert H. schulstat, Middletown. N. J.

Application May 15, 1946, Serial No. 669,919

rlhis invention relates to refrigeration systems and particularly to asystem in which the refrigerant fluid employed is of the organic type,such for instance as methyl chloride, methylene chloride, or thecommercially well-known Freon c l2 or Freon 22.

Two of the characteristics of the organic refrigerants above mentionedare that none of them is miscible with water and each is heavier thanwater, and consequently the latter floats on the refrigerant when it isin its liquid form. These characteristics are, from a certain viewpoint,disadvantageous when moisture is present in the lines of a mechanicalrefrigeration system charged with one of these organic refrigerants.This arises from the fact that the moisture, which collects on top ofthe refrigerant in the storage tank of the systemy as a result of thedifference in specic gravities, tends to freeze on the usual expansionvalve should the system spring an undetected leak and the water besiphoned out .of the storage tank and transmitted through the system tothe expansion valve. To prevent this, it is customary to include in thesystem between the refrigerant storage tank and the expansion valve a dehydrator which is charged with a drying agent of a deliquescent nature,such for example as silica gel. 'I'he primary purpose of this dehydratoris to absorb the moisture in the refrigerant before the latter reachesthe expansion Valve.

The dehydrators now in use are very eifective as long as the dryingagent contained therein is not exhausted. When the drying agent issaturated the dehydrator no longer serves any useful purpose until suchtime as the exhausted lagent is replaced with a fresh charge. One of theshort-comings of the dehydrators now in general use is that no means isincorporated therein which will indicate when the drying agent isexhausted. Without such indication, it is diflicult to know exactly whento replace the charge.

Therefore, it is the primary object of the present invention to providean improved refrigeration system having contained therein means forindicating the presence of moisture in the refrigerant.

Another object of the present invention is to provide a refrigerationsystem dehydrator which not only indicates the presence of moisture inthe refrigerant but also indicates when the drying agent contained inthe dehydrator is approaching exhaustion.

2 Claims. (Cl. B10-131) A -further object of the invention is to provide`a refrigeration system dehydrator having visible means indicating thepresence of moisture in an organic refrigerant `and `also the exhaustionof the charge of drying agent in said dehydrator.

Gtherobiects-of the invention will appear from the following descriptiontaken in connection with the drawings, which form a part of thisspecification, and in which:

Fig. l is a vertical longitudinal sectional view of a preferredembodiment of the present invention.

Fig. "2 is an elevational view of the dehydrator shown in Fig. l, with--some of the drying agent at the bottom of the device having absorbedmoisture and consequently changed color, there by indicating not onlythe presence of moisture in the system but also the amount of dryingagent not yet exhausted.

Fig. 3 is a bottom plan View of the outlet conduit, Vshowing the mannerin which the moisture deecting ns are attached thereto.

Fig. 4 is a View similar to Fig. l, but showing a modication of thedevice.

Fig. 5 is a diagrammatic view of a refrigeration system havingincorporated in it my improvement.

Referring now more particularly to Fig. 5, I have shown a refrigerationsystem including a cooling tank or evaporator I housing an expansion`coil II connected at its delivery end by a conduit I2 to the intakeside of a conventional compressor I3. The outlet side of the compres'sor I3 is connected by a conduit I4 to a condenser I5 cooled by means ofa motor-driven fan IB. The condenser is connected by a conduit `Il to arefrigerant storage vor receiver tank i8. Refrigerant in the storagetank I3 is delivered through the conduit I9 and shut-01T valve 20 to anexpansion valve 2! located at the receiving end of the expansion coil II. Connected in `the line I9 between the storage tank I and theexpansion valve 2| is my improved indicating dehydrator identiiiedgenerally as 22. The system shown in Fig. 5, with the exception of theindicating dehydrator 22, is conventional and operates in the usualWell-known manner, Suflice herein to say that the refrigerant upon`leaving the expansion coil I I through the conduit I2 is in a gaseousstate at low pressure. The compressor I3 increases the pressure of thegas, after which the condenser I5 cools the high pressure gas which isthen delivered to the storage tank `I8 in liquid form. From the storagetank the liquid refrigerant is delivered by the conduit I9 to theexpansion valve 2l where the pressure of the liquid refrigerant isreduced, converting the refrigerant into a low pressure liquid .or gas.During the operation of the system the above described cycle is ofcourse continuous.

In practice the refrigerating systems sometimes spring a smallundetected leak through which the refrigerant is gradually lost. It willbe appreciated that small leaks do occur in the system owing to the factthat the organic refrigerants are strongly solvent and that the leaksmay be undetected because the organic refrigerants most widely employedtoday are odorless. When the level of the refrigerant in the storagetank drops, as a result of the leak, any moisture which may be floatingon top of the refrigerant in the storage tank is lowered to a levelwhere it is siphoned into the system.- Unless removed from the system,this moisture is led to the expansion valve 2| where, as a result of thefunctioning of the valve, the temperature is dropped to a point wherethe moisture freezes in the expansion valve and interferes with itsproper operation. In fact, in new installations where moisture isinvariably present, this condition frequently causes a completebreakdown. In an effort to eliminate this defect, it has become commonpractice to connect, in the line between the storage tank and theexpansion valve, a dehydrator the function of which is to remove themoisture from the refrigerant as the latter travels through thedehydrator. The commercial dehydrators now on the market are successfulin removing the moisture from the refrigerant as long as the dryingagent in the dehydrator has not been subjected to sufficient moisture toexhaust the drying agent of its absorption powers. If thisrshould occur,the dehydrator is useless until the charge of drying agent can bereplaced. It is the purpose of the present invention to provide adehydrator which is designed to indicate when its charge of drying agentis exhausted. In its preferred form, my improved dehydrator indicateswhen moisture is present in the system and also indicates theprogressive exhaustion of the drying agent, thereby giving ample warningbefore the charge of drying agent is completely exhausted so that it canbe replaced at the proper time. Referring to Fig. 1, I have shown apreferred embodiment of my dehydrator comprising a casing including ametallic bottom end-cap 23, a metallic top end-cap 24 and a tubularVbodymember 25 of transparent material, preferablyl Pyrex glass,interposed between and suitably secured to said end-caps 23 and 2 4. Theendcap 23 is provided with a threaded inlet duct or bore 26 into thelower end of which is threaded a conventional pipe-fitting 21 on theconduit I9. The top end-cap 24 has a threaded outlet duet or bore 28into which is threaded a pipe-fitting 29 on the conduit I9. Removablythreaded in the inlet bore 26 of the bottom end-cap 23 is a screw-plug30 having a central hole 3| and a reduced liange 32. Soldered orotherwise secured to the flange 32 is a vertically disposed tubularinlet screen 33 closed at its upper end. To provide for removing thescreen 33 to permit a re-` charging of the drying agent, the screw-plug30 is formed with a screw-driver slot 34 which is rendered accessible byremoving the pipe-fitting 21.

Threaded in the outlet bore 28 of the top endcap 24 is a screw-plug 35with a central opening in which is soldered or otherwise fastened theupper end of an outlet tube 36 depending within the tubular body 25. Atits lower open end the 4 tube 36 has secured to it sheet-metal fins 31the function of which will be later described. To provide for theremoval of the tube 36, the screwplug 35 is preferably formed with ascrew-driver slot 38.

Disposed within the transparent Pyrex body 25 is a charge of dryingagent 39 which, according to the present invention, has capacity forchanging color upon the absorption of moisture. A drying agent which Ihave found to be entirely satisfactory is silica gel treated with cobaltchloride which imparts to the silica gel a blue color. When the bluesilica gel comes into contact with moisture, it changes color from itscharacteristic blue to a pink. With the above in mind, it will -beobvious that, in the event moisture is present in the refrigerant as itpasses up through the dehydrator, the blue silica gel within thetransparent tubular body 25 will not only absorb the moisture, but indoing so will also change color from a blue to a pink. This changeofcolor of the silica gel is visible through the transparent body 25.Therefore by merely looking at the dehydrator the observer is aware thatmoisture is present in the system. Also, the percentage of the chargestill available can be readily seen. Fig. 2 shows the dehydrator infront elevation with the lower portion of the drying agent chargeexhausted and consequently pink in color, while the upper portionthereof is still effective and therefore blue in color.

Referring to Fig. 1, it will be seen that on top of the drying agent 39there is located a filter preferably having the form of two spaced disksof line mesh wire screen 49 and 4I between which there is disposed ahair felt pad 42. The filter serves to prevent small dislodged particlesof the dehydrating agent 39, which undergoes more or less continuousmovement while the dehydrant is in effective operation, from beingtransmitted into the system. It will -be evident that the filter pad isspaced from beneath the top end-cap 24 to provide a cavity 43 which,during'the normal operation of the system, is lled with the refrigerant.The refrigerant, in traveling from the cavity 43 through the outlet bore28 of the end-cap 24, must enter through the lower open end of the tube36. In the event moisture gets past the dehydrant 39, it will rise tothe top of and float on the refrigerant at a level above that of thelower end of the tube 36. In other words, that portion of the cavity 43above the level of the lower end of the tube 36 forms, in effect, a trapfor collecting any' moisture which may escape the drying agent 39. Topreclude the moisture which escapes the drying agent 39 from enteringdirectly into the open end of the tube 36 as it is rising to the top ofthe refrigerant, there are provided the iins 31 which, function as guidemeans for directing the beads of moisture out of range of the lower openend of the tube 36.

Fig, 4 represents a modification of the dehydrator shown in Figs l to 3,inclusive. In the modiiication, the casing includes a bottom end-cap 44,an upper or top end-cap 45 and a transparent tubular body-member 46,preferably of Pyrex glass. The two end-caps and the tubular body aremaintained in assembled relation by means of a centrally disposedassembly-rod 41 threaded at its upper end into the end-cap 45 and at itslower end slidably fitted in a central bore 48 formed in the lowerend-cap 44. The projecting portion of the lower end of the assembly-rod41 is threaded, as at 49, to receive the square or hexagonal locking-nut59, which when tightened effectively clamps the tubular body 46 betweenthe two end-caps 44 and 45, and which provides means for disassemblingthe dehydrator to replace the dehydrant charge. In order to preventleakage between the tubular body 46 and the endcap 44 and 45, the twoend-caps are each formed with a circular channel i into which projectsthe end of the tubular body 46, there being interposed between the endof the tubular body and the bottom of the channel 5I a resilientringgasket 52. To preclude leakage along the bore 48 between the end-cap44 and the assembly-rod 41, there is provided a resilient ring-gasketv53 which is placed under pressure by the lockingnut 50 when the latteris tightened to maintain the unit in assembled relation.

To provide an inlet for the refrigerant, the assembly-rod 41 islongitudinally bored at its lower end to form a duct 54 which isintersected adjacent its upper end by the four radial ports 55.Surrounding the assembly-rod 41 immediately above the lower end-cap 44is a lter comprising spaced disks of ne mesh bronze-wire 56 and 51having interposed between them a pad 58 preferably of bronze wool.Resting on the lter is the charge of drying agent 60 which, like thedrying agent 39 in the preferred embodiment of the device, has thecapacity of changing color as it becomes saturated with water. Disposedon the top of the charge of drying agent is a second lter comprising twospaced disks of ne mesh bronze- Wire 6| and 62 between which is a pad63, preferably of hair felt. After passing up through the dehydrant 60and the top lter, the refrigerant is delivered through the radial ports64 into a central duct 65 in the upper portion of the assemblyv;-

rod 41. It will be seen that the radial ports 64 are spaced down fromthe end-cap 45 for the purpose of providing a closed cavity above theports 64 to trap any moisture which may escape the dehydrant 50.

From the above description, it will be understood that I have provided arefrigeration system having means for indicating the presence ofmoisture in said system. Not only is the presence of moisture indicatedimmediately as it travels through the system, but it is absorbed beforeit can do any damage. Also, the period of eifectiveness of thedehydrator readily can be observed, with the result that maximum lifecan be obtained from the dehydrator without fear of using the samebeyond the effective life of its charge. While I have shown the tubularbody of the dehydrator as being made of transparent glass, it will beunderstood that the same may be made of metal or the like tted with ajudicially arranged transparent sight through which the change of colorof the drying agent may be visible. Also, while I desire to use a dryingagent which changes color upon contact with water, the invention in itsbroadest aspect may be considered to cover an agent which changes itsshape or size or form upon contact with water, as long as such change incharacter may be discernible through the transparent portion of the bodyof the device.

Having thus set forth the nature of the invention, what I claim hereinis:

1. A dehydrator adapted for use in abstracting water from the medium ofa refrigeration system, comprising a body-member having an inlet at itslower end, a top end-cap secured to said body-member, a charge of dryingagent contained in said body-member and spaced `below said top end-cap,an outlet tube secured to said top endcap and depending within saidbody-member with its lower open end spaced below said top endcap andterminating above said drying agent to provide a cavity above the loweropen end of the tube for trapping any water which may escape past saiddrying agent, and a bale device disposed at the lower open end of saidoutlet tube to deflect water out of range of said lopen end should anywater escape through said drying agent.

2. A dehydrator adapted for use in abstracting water from the medium ofa refrigeration system, comprising a body-member having an inlet at itslower end, a top end-cap secured to said bodymember, a charge of dryingagent contained in said body-member and spaced below said top endcap, anoutlet tube secured to said top end-cap and depending within saidbody-member with its lower open end spaced below said top end-cap andabove the top of said drying agent charge to provide a cavity above thelower open end of the tube for trapping any water which may escape pastsaid drying agent. and a baille in the form of plate-like iins havinginclined edges disposed at the lower open end of said outlet tube tolead the beads of water away from the open end of said tube should anywater escape through said drying agent.

HERBERT H. SCHULSTADT.

REFERENCES CITED The following references are of record in the file ofthis patent:

UNITED STATES PATENTS Number Name Date 650,149 Howard May 22, 19001,281,064 Pfanstiehl Oct, 8, 1918 1,601,308 Hill Sept. 28, 19281,914,829 Imhoff et al June 20, 1933 1,917,121 Hughson July 4, 19332,199,258 Gray Apr. 30, 1940 2,210,862 Tronstad Aug. 6, 1940 2,232,025Glisan Feb- 18, 1941 2,243,949 Fox June 3, 1941 2,260,608 Cormack Oct.28, 1941 2,323,160 Stecher et al June 29, 1943 2,325,657 Burkness Aug.3, 1943 FOREIGN PATENTS Number Country Date 437,139 Great Britain Oct.24, 1935 784,957 France July 30, 1935

